Add time reporting

[niclaslindstedt]

List time reports:

etimo time list

Add time report:

etimo time add 8

Adds 8 hours today

etimo time add 8 20

Adds 8 hours on the 20th of this month.

etimo time add 8 12 13 14 15

Adds 8 hours on the 12th, 13th, 14th and 15th of this month.

Remove time report:

etimo time remove 20
etimo time remove 11-20
etimo time remove 2020-11-20

Removes the latest date ending with 20, 11-20 or 2020-11-20.

Since we're time reporting each month we shouldn't need to specify the entire date.